package com.lib.utils;

import android.text.TextUtils;

import java.io.File;
import java.io.FileInputStream;
import java.math.BigInteger;
import java.security.MessageDigest;

public class MD5Utils {

    public static String md5(String string) {

        if (TextUtils.isEmpty(string)) {
            return "";
        }
        MessageDigest md5;
        try {
            md5 = MessageDigest.getInstance("MD5");
            byte[] bytes = md5.digest(string.getBytes());
            StringBuilder result = new StringBuilder();
            for (byte b : bytes) {
                String temp = Integer.toHexString(b & 0xff);
                if (temp.length() == 1) {
                    temp = "0" + temp;
                }
                result.append(temp);
            }
            return result.toString();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "";
    }

    /**
     * 获取单个文件的MD5值！
     *
     * @param file
     * @return
     */
    public static String getFileMD5(File file) {

        if (!file.isFile()) {
            return "null";
        }
        MessageDigest digest = null;
        FileInputStream in = null;
        byte buffer[] = new byte[1024];
        int len;
        try {
            digest = MessageDigest.getInstance("MD5");
            in = new FileInputStream(file);
            while ((len = in.read(buffer, 0, 1024)) != -1) {
                digest.update(buffer, 0, len);
            }
            in.close();
        } catch (Exception e) {
            return "null";
        }
        BigInteger bigInt = new BigInteger(1, digest.digest());
        return bigInt.toString(16);
    }
}